~ Holy Communion
That although we acknowledge that we cannot be without sin, yet still we ought not to suspend ourselves from the Lord?s Communion. Yet we ought not to suspend ourselves from the Lord?s Communion because we confess ourselves sinners, but should more and more eagerly hasten to it for the healing of our soul, and purifying of our spirit, and seek the rather a remedy for our wounds with humility of mind and faith, as considering ourselves unworthy to receive so great grace. Otherwise we cannot worthily receive the Communion even once a year, as some do, who live in monasteries and so regard the dignity and holiness and value of the heavenly sacraments, as to think that none but saints and spotless persons should venture to receive them, and not rather that they would make us saints and pure by taking them. And these thereby fall into greater presumption and arrogance than what they seem to themselves to avoid, because at the time when they do receive them, they consider that they are worthy to receive them. But it is much better to receive them every Sunday for the healing of our infirmities, with that humility of heart, whereby we believe and confess that we can never touch those holy mysteries worthily, than to be puffed up by a foolish persuasion of heart, and believe that at the year?s end we are worthy to receive them. Wherefore that we may be able to grasp this and hold it fruitfully, let us the more earnestly implore the Lord?s mercy to help us to perform this, which is learnt not like other human arts, by some previous verbal explanation, but rather by experience and action leading the way; and which also unless it is often considered and hammered out in the Conferences of spiritual persons, and anxiously sifted by daily experience and trial of it, will either become obsolete through carelessness or perish by idle forgetfulness.
Abbot Theonas
Third conference of Abbot Theonas, Chap XXI, , in John Cassian
~ Church Attendance
So we come to church, to our true home, and we are truly glad. This is the greatest privilege which a Christian can have. Here we experience the grace of God. We experience our salvation, the results of the redemptive work of our God, of Christ, the great "High Priest" (Heb 2.17; 5.9-10; 7.24-27). Here, in church, we acquire a sense of the Apostle's words: "Christ, through his own blood, entered once for all into the Holy Place ... thus securing eternal redemption" (Heb 9.12). Christ lives for us, he prays for us, and raises his hands to the heavenly Father. He shed his blood for us only once. He entered into the Holy of Holies only once, and, from that day, he has not ceased to urge the saints - and particularly His Mother, Our Lady - to intercede for us to the heavenly Father, for our hearts, for our sins, for our pains, for the disappointments of our life. Once and for all he entered into heaven, where he remains eternally, never again to leave the throne where he took his place "at the right hand of the heavenly Father" (cf. Mk 16.19; Heb 10.12; 12.2). This means that coming to church to attend the Divine Liturgy is not a random act or chance occurrence. It isn't something about which you can say: Don't worry, it doesn't matter, I'll come tomorrow, or the day after tomorrow. No. It's a unique act. We go to him whom we have loved, to him who gave his life for us, to Christ.
Elder Amilianos of the Holy Monastery of Simonopetra
~ Attending Church
St. John Climacus was asked if there are reliable signs by which it's possible to know whether a soul is drawing near to God or moving away from Him. After all, regarding ordinary things there are clear signs as to whether they're good or not. When, for instance, cabbage, meat or fish begins to rot, it's easy to notice it, since the rotting object begins to give off a foul odor, the color and taste change, and its external appearance witnesses to its deterioration. Well, and what about the soul? After all, it's bodiless and can't give off a bad smell or change its appearance. To this question the Holy Father replies, "A sure sign of the deadening of the soul is the avoidance of church services."
A man who is growing cold towards God begins first of all to flee attending church. At first he tries to come to services later, and then he ceases altogether to visit God's temple.
Elder Barsanuphius of Optina
~ Remaining in Church
Blessed Matthew of the Caves resembled the first Holy Evangelist not only in name but also in deeds. This blessed man gave himself over to ascetic toil in the Caves Monastery and received from God the great gift to see the enemies of mankind - the demons - and to know their hidden snares and devices. In revealing them to others, he served for the good and salvation of the brethren.
Once, while standing in his usual place during a church service, Blessed Matthew saw an invisible demon in the image of a a warrior. The demon moved about the church throwing some sort of sticky petals on the brethren. If one of the petals fell on a brother and remained on him, his attention to the divine service immediately weakened and his fervour toward prayer was lost. The brother would find some excuse for himself, quickly leave the church for his cell, and go to his cell where he would lie down to sleep and not return to church. When Blessed Matthew revealed this to the brethren, they became especially watchful and attentive and resisted the temptation to leave the church during a service.
Kiev-Pechersky Patericon
The Life of Matthew the Prophet, from the Kiev-Pechersky Patericon